1. Field of the Invention
The present invention relates to a magnetic recording and reproducing apparatus in which a magnetic tape is automatically mounted on a tape guiding drum containing therein rotary magnetic heads so that signals can be recorded on or reproduced from the tape.
2. Description of the Prior Art
As video tape recorders for domestic purpose have been developed, there have been proposed various magnetic recording and reproducing apparatuses of the type in which magnetic tapes are helically mounted on tape guiding drums containing rotary magnetic heads so that signals can be recorded on or reproduced from the tapes. With this type of magnetic recording and reproducing apparatuses, the magnetic tape must be mounted on the tape guiding drum such that the tape extends around more than one half the peripheral surface of the drum. The tape mounting operation was very troublesome and needed a high degree of accuracy. Accordingly, mechanisms have been proposed to automatically mount magnetic tapes on tape guiding drums of magnetic recording and reproducing apparatuses.
The proposed automatic tape mounting mechanisms are classified into two types, one of which is disclosed in, for example, U.S. Pat. No. 4,045,820 issued Aug. 30, 1977 to Staar, and is so constructed that tape drawing members or tape guiding fingers are operated solely by link mechanisms. Because of this construction, the automatic tape mounting mechanism has difficulties in that the mechanical accuracy of the link mechanisms greatly influences the tape mounting operation with a resultant failure to precisely mount tapes on the tape guiding drum and that a large number of structural elements or components are required. The other or second type of automatic tape mounting mechanism is disclosed in, for example, japanese Pre-Examination Patent Publication No. 134,410/77 and No. 134,411/77 corresponding to U.S. Pat. Nos. 4,126,888 and 4,115,825 respectively issued Nov. 21, 1978 and Sept. 19, 1978 to Hayashi et al, and is so constructed that tape drawing members are operated by the rotation of rotary discs or rings disposed beneath the tape guiding drum. The rotary discs or rings are of diameters larger than that of the tape guiding drum and not only make the entire apparatus large-sized but also produce dead spaces therein. In addition, the mechanism for rotating the rotary discs or rings is of complicated structure and requires a large number of components.